TABLE 1.
Overview of demographic and clinical characteristics of the study population during hospital admission
| Total# | WHO ordinal scale 3 ¶ | WHO ordinal scale 4+ | WHO ordinal scale 5–7 § | |||||
| n | n | n | n | |||||
| Demographics | ||||||||
| Male sex | 262 | 151 (58) | 91 | 43 (47) | 126 | 74 (59) | 45 | 34 (76) |
| Age at discharge years | 262 | 58.6±14.2 | 91 | 55.8±14.8 | 126 | 60.0±14.8 | 45 | 60.3±10.2 |
| Education, two levels | 239 | 130 (54) | 83 | 55 (66) | 115 | 56 (49) | 41 | 19 (46) |
| Body mass index kg·m−2 | 249 | 28.3±4.7 | 85 | 27.2±4.6 | 121 | 28.8±4.8 | 43 | 29.1±4.2 |
| Smoking history | ||||||||
| Never | 229 | 133 (58) | 79 | 52 (66) | 109 | 61 (56) | 41 | 20 (49) |
| Former | 229 | 90 (39) | 79 | 25 (32) | 109 | 45 (41) | 41 | 20 (49) |
| Present | 229 | 6 (3) | 79 | 2 (2) | 109 | 3 (3) | 41 | 1 (2) |
| Comorbidities | ||||||||
| Diabetes mellitus | 262 | 22 (8) | 91 | 1 (1) | 126 | 14 (11) | 45 | 7 (16) |
| Hypertension | 239 | 80 (33) | 83 | 23 (28) | 115 | 45 (39) | 41 | 12 (29) |
| COPD | 262 | 13 (5) | 91 | 5 (5) | 126 | 6 (5) | 45 | 2 (4) |
| Obesity | 249 | 78 (31) | 85 | 19 (22) | 121 | 41 (34) | 43 | 18 (42) |
| Charlson comorbidity index | ||||||||
| 0 | 262 | 186 (71) | 91 | 72 (79) | 126 | 85 (67) | 45 | 29 (64) |
| 1 | 262 | 43 (16) | 91 | 10 (11) | 126 | 24 (19) | 45 | 9 (20) |
| ≥2 | 262 | 33 (13) | 91 | 9 (10) | 126 | 17 (13) | 45 | 7 (16) |
| Hospital stay | ||||||||
| Length of stay days, median (IQR) | 260 | 6 (3–12) | 90 | 3 (1–4) | 125 | 7 (5–11) | 45 | 19 (16–28) |
| ICU stay | 262 | 51 (19) | 91 | 1 (1) | 126 | 8 (6) | 45 | 42 (93) |
| No. of days, median (IQR) | 11 (5–15) | 4 (4–4) | 2.5 (3–1) | 12 (7–16) | ||||
| Invasive mechanical ventilation | 255 | 35 (14) | 91 | 0 | 125 | 0 | 45 | 35 (78) |
| No. of days, median (IQR) | 10 (8–15) | n/a | n/a | 10 (8–15) | ||||
| ECMO | 250 | 1 (0.4) | 91 | 0 | 126 | 0 | 45 | 1 (2) |
| WHO ordinal scale for clinical improvement | ||||||||
| 3: No supplemental oxygen | 262 | 91 (35) | 91 | 91 (100) | ||||
| 4: Supplemental oxygen | 262 | 126 (48) | 126 | 126 (100) | ||||
| 5: Noninvasive ventilation or high-flow O2 | 262 | 10 (4) | 45 | 10 (22) | ||||
| 6: Invasive mechanical ventilation | 262 | 34 (13) | 45 | 34 (76) | ||||
| 7: Invasive mechanical ventilation and additional organ support | 262 | 1 (0.4) | 45 | 1 (2) | ||||
| Chest radiograph | ||||||||
| Normal | 244 | 79 (32) | 79 | 39 (49) | 121 | 37 (31) | 44 | 3 (7) |
| One-sided opacities | 244 | 43 (18) | 79 | 17 (21) | 121 | 21 (17) | 44 | 5 (11) |
| Bilateral opacities | 244 | 122 (50) | 79 | 23 (29) | 121 | 63 (52) | 44 | 36 (82) |
| Blood sampling at admission | ||||||||
| pHƒ | 229 | 7.46±0.05 | 73 | 7.46±0.05 | 116 | 7.46±0.05 | 40 | 7.46±0.07 |
| PaO2ƒ kPa/mmHg | 231 | 9.8±2.2/73.5±16.5 | 73 | 11.0±2.4/82.5±18.0 | 117 | 9.4±1.9/70.5±14.2 | 41 | 8.8±2.1/66.0±15.7 |
| PaCO2ƒ kPa/mmHg | 231 | 4.4±0.9/33.0±6.7 | 73 | 4.5±0.7/33.7±5.2 | 117 | 4.3±0.7/32.2±5.2 | 41 | 4.4±1.4/33.0±10.5 |
| Base excessƒ mmol·L−1 | 223 | 2.1±1.9 | 70 | 1.7±1.1 | 113 | 2.3±2.1 | 40 | 2.1±2.1 |
| Lactate mmol·L−1ƒ | 218 | 1.3±1.5 | 70 | 1.1±0.5 | 109 | 1.2±0.7 | 39 | 1.8±3.2 |
| Haemoglobin g·dL−1## | 261 | 13.9±1.6 | 91 | 13.9±1.6 | 126 | 14.0±1.4 | 44 | 13.7±1.9 |
| C-reactive protein mg·L−1¶¶, median (IQR) | 260 | 105 (33–190) | 90 | 31 (6–63) | 126 | 120 (59–174) | 44 | 264 (178–338) |
| Ferritin µg·L−1¶¶ | 223 | 1428±1750 | 72 | 660±1006 | 108 | 1346±1367 | 43 | 2918±2531 |
| Lymphocyte count## (×109·L−1) | 248 | 1.2±0.9 | 84 | 1.4±0.9 | 121 | 1.1±0.7 | 43 | 0.9±0.6 |
Data are presented as n (%) or mean±sd unless otherwise stated. WHO: World Health Organization; sd: standard deviation; COPD: chronic obstructive pulmonary disease; IQR: interquartile range; ICU: intensive care unit; ECMO: extracorporeal membrane oxygenation; PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension. #: n=262; ¶: n=91; +: n=126; §: n=45; ƒ: arterial blood analysis at admission; ##: minimum levels during hospital stay; ¶¶: maximum levels during hospital stay.